Hitherto, as this type of lid lock device, a lid lock device which includes a worm gear and a worm wheel provided on a power transmission path where the power of a motor is transmitted to a lock member is known (for example, JP 2010-106437A (Reference 1) (FIG. 3)).
However, in the above-described lid lock device of the related art, for example, when foreign matter such as sand particles infiltrates between the lock member and a housing and results in an increase in the resistance against the movement of the lock member and thus the output of the motor is increased, there are problems in that the worm wheel is deformed to deviate from the worm gear and this results in disengagement therebetween and the output of the motor cannot be used in a high torque range.